recipes-bsp/u-boot: u-boot-master: use official git.u-boot-project.org source URL

[CMeierSoftware]

Description

Summary

Updates GIT_URL in u-boot-master.bb to point to the current official U-Boot source repository instead of the legacy source.denx.de host.

Motivation

Per the official U-Boot documentation (https://docs.u-boot.org/en/latest/build/source.html), the canonical source is now hosted at git.u-boot-project.org, with GitHub maintained only as a mirror:
git clone https://git.u-boot-project.org/u-boot/u-boot.git

source.denx.de has also been intermittently unreachable (observed HTTP 502 errors), which causes BitBake parsing to fail entirely for this recipe since SRCREV = "${AUTOREV}" requires a live git ls-remote during parse time:

FetchError: Fetcher failure: ... git ls-remote https://source.denx.de/u-boot/u-boot.git
failed with exit code 128, output:
error: RPC failed; HTTP 502 curl 22 The requested URL returned error: 502

Changes

• GIT_URL: git://source.denx.de/u-boot/u-boot.git;protocol=https → https://git.u-boot-project.org/u-boot/u-boot.git;protocol=https

Testing

• git ls-remote https://git.u-boot-project.org/u-boot/u-boot.git succeeds
• Recipe parses and SRCREV = "${AUTOREV}" resolves correctly with bitbake -p